Hydrogen can be produced by means of fuel processing. In a fuel processor, a hydrocarbonaceous fuel is converted into a hydrogen-rich gas stream that may for instance be used in a fuel cell for the generation of electricity.
Typically in a fuel processor, the hydrocarbonaceous fuel is reacted with oxygen and/or steam by means of catalytic partial oxidation, autothermal reforming, steam reforming or a combination of one or more thereof to obtain a gas mixture comprising carbon oxides and hydrogen.
During operation the catalyst may be deactivated. Such a deactivation of the catalyst may be induced by any number of mechanisms, including coking, poisoning and reduction. Consequently, fuel conversion and hydrogen yield decrease and periodic replacement or regeneration of the catalyst is necessary. Typical catalyst used in for instance catalytic partial oxidation and steam-reforming processes comprise Group VIII noble metals. Such metals are expensive and therefore it is desirable to regenerate the catalyst rather than replacing it.
A known method for regeneration of a catalyst is oxidative regeneration. U.S. Pat. No. 7,005,455 discloses a method for in-situ regenerating a partial oxidation catalyst. In the method of U.S. Pat. No. 7,005,455 the catalyst is regenerated by passing a gas over a deactivated catalyst that restores the active surface area of the catalytic metals, which was lost from deactivation phenomena. In one embodiment of U.S. Pat. No. 7,005,455 a single syngas reactor is operated in cyclic mode in which the reactor alternates between reaction and regeneration operating conditions. It is disclosed in U.S. Pat. No. 7,005,455 that once deactivation of the catalyst is detected, a regeneration gas replaces reactant feedstock to the reactor. Reactivation will take place for a period of time sufficient to restore activity of the catalyst. It is suggested in U.S. Pat. No. 7,005,455 that independent of the catalyst deactivation the catalyst is reactivated for three hours per week. During this period the reactor produces no hydrogen.
There is a need in the art for a process for producing hydrogen, which will enable a regular supply of hydrogen without the need for prolonged shutdown periods and the need for separate regeneration gases.